1. Field of the Invention
The present invention relates to a device for extracting one at a time approximately cubically shaped containers, formed of a thin film material such as polyethylene and used to hold food or chemical products which are in a liquid state, from a plurality of triangularly folded stacked containers and transferring the extracted container to the next processing step (for example, to the filling position for receipt of the liquid material to be contained).
2. Background Art
A cubically shaped container 1, such as that shown in FIG. 11, formed from a thin flexible film material such as polyethylene, is widely used as a container convenient for use in the transportation of liquid materials such as soy sauce or mirin (Japanese rice wine) or of industrial chemicals. A pour spout 3 is formed below the edge of one surface of container 1, and is closed by twist-on cap 2. Container 1 is filled via pour spout 3 with the liquid to be contained. As is shown in FIG. 13, pour spout 3 has a flange 4a and comprises a thread ring 4 into the outer surface of which a screw thread 4b, onto which cap 2 is screwed, has been cut. When container 1 is empty, thread ring 4 is retracted back in a position within container 1 thereby allowing container 1 to present a flat outer surface which facilitates even stacking.
Prior to filling container 1 with a liquid material, that is to say in the case where transporting and depositing several empty containers, one half of the container is folded within the other half of the container by being inverted along the diagonal plane which extends between a pair of diagonally opposing edges and passes through the center of the container, as is shown in FIG. 12. By thus folding the containers, the empty space therein is almost completely compressed and the containers 1, when stacked and viewed from the side, have a triangular shape. As shown in FIG. 14, a stacked configuration 1A of containers 1 is formed by stacking several thus folded containers on top of one another.
However, in extracting one at a time containers 1 from the stacked configuration 1A of containers 1 and filling with the material to be contained, it sometimes occurs that the rigidity of the container 1 itself is low therefore making handling difficult. It was therefore not possible to eliminate reliance on manual labor, this creating a serious impedance to automation. Moreover, where filling container 1 with a liquid product for consumption, in consideration of the strict hygienic standards demanded in this case, it was highly desirable to eliminate the reliance on human labor by automating the process wherein containers 1 are extracted one at a time from stacked configuration 1A of containers 1 and transferred to the next processing step.